On ike different Sorts of Lime ufed in Agriculture. 44J 



■ this piirpofe-alfo the fecond was repeated upon a piece of lime-ftone, prcvioufly pow- 

 dered to render every part of it the fame (juality. The firft column {hews the quantity 

 of calcareous fpar which might have been difl'olved hy the acid required to take up the 

 magnefia. Tlie fecond {hews the correfponding quantites of magnelia in 35 grs. of 

 each rub{lance. . The tliird exprciles tlie quantity of }ime. This was inferred by 

 fubtrafting the weight of the magnefia and of the iron and clay from 13,2 grs. the 

 weight of the whole quantity of earth in 25 grs. of lime-ftone. This is probably not 

 very incorrefl, as in two fpecimens which differed moft in the proportion of magnefia 

 and lime ; the weight of the two earths was nearly the fame. 



A piece of dolomite from Rome, was wrapped in a thin piece of platina, that no 

 part of it might be lofl, and being then expofed to a llrong heat left of earth — 32,9 per 

 Cent. 



Dolomite from Mount Vefuvius . . 52,8 



Breedon lime-flone . . . 52,4 ' 



Calcareous fpar left of lime ^ . . 55.8 



In three of the experiments alfo the calcareous earth was precipitated by mineral 

 alkali ; and the quantity of it being tried by that of the marine acid required to diifolve 

 it, it correfponded very nearly with that put down. 



A quantity of marine acid which would diffolve. 15 grs. of calcareous fpar, would 

 alfo diffolve 5,5 of calcined magnefia, and 2,5 grs. of fpar; fo that 12,5 grs. of fpar, 

 required the fame quantity of acid as 5,5 grs. ot magnefia. 



The magnefia ufed was pure, and made red hot immediately before it was weighed. 



Subjiances examined. ^Quavtity of Spar which 



the Add required to 

 take up the Magnrjia 

 would have dijjolved. 



Mixture of 5,5. grs. of mag- 

 nefia, and 14 grs. of cal- 

 careous fpar . . . . 



or grs. of Breedon lime-flone 

 previoufly powdered . . 



®5 g"^^- ^'■"'^ P^*^* ^^ ''^^ 

 fame powder . . . • 



jc grs. of dolomite from 

 Rome 



dolomite froni lona 



Tot. III. January xSoo. 



12.5. 



".53 



11.56 



12,2 

 10,1 



Quantity of 

 Mugnejia. 



5^5 



5,082 



5.37 

 4.4 



Quantity of 

 Lime. 



7.8 

 7.929 



7.9 » 3 



7.73 

 7.8 



Iron and Clap. 



.2 



.2 



3M 



{infoluble 

 fubfianoe 



Vefuviiaji. 



